The present invention, in some embodiments thereof, relates to nanotechnology and, more particularly, but not exclusively, to a nanostructure, a process of producing same and a system containing and utilizing same.
In recent years, one dimensional (1D) nanomaterials such as carbon nanotubes and semiconductor nanowires/nanotubes have been intensively explored as potential building blocks for multiple electronic, optoelectronic and biosensing applications. Extensive efforts have been devoted to the synthesis of semiconductor nanowires with controlled chemical and physical properties such as: dimension, chemical composition, doping and crystal structure. Such shaped-controlled semiconductor nanowires are recognized as capable of exhibiting novel electrical and optical properties, and of being efficiently utilized in the fabrication of devices with fewer welding joints and improved electrical connections.
However, although some significant synthetic advances were achieved, the ability to control nanowire's geometry has been significantly limited.
A certain limited degree of complexity in silicon nanowire geometry was recently demonstrated using a ‘nanotectonic’ approach [Tian et al. Nat Nanotechnol 2009, 4, (12), 824-9]. This methodology provides iterative control over nanowire nucleation and growth, affording kinked silicon nanowires in which straight sections of controllable length are separated by 120° triangular joints. Nanowires geometries obtained by this method are limited to kinked triangular nanowire structures.
WO 2011/038228 discloses bent nanowires, having one or more kinks and a defined crystallographic orientation. Methods of preparing such nanowires are also disclosed.
In another report [Chen et al. Nano Letters 2010, 10, (3), 864-868], a metal-assisted chemical etching approach was employed, allowing the synthesis of zigzagged silicon nanowires with 150°, 125° or 90° turning angles by controlling the crystallographic orientation of the Si mother wafer, reaction temperature, and etchant concentration.
Wavy carbon nanotubes serpentines structures were also synthesized by a crystalline surface-directed “nanotube epitaxy” method [Geblinger et al. Nat Nano 2008, 3, (4), 195-200].
The overall quality of the as-synthesized nanowires is rather low and the shape of the nanowires obtained varies along the wafer surface. The currently known methodologies therefore lead to nanowires of limited-controlled shapes, and further, to nanowires that must be harvested from the donor substrates if further fabrication of devices is required.
Additional background art includes U.S. Pat. No. 7,538,337.